Lithodora diffusa 'heavenly blue'

Selected cultivar of Glandora diffusa, this perennial sub-shrub of the Boraginaceae family is one of the oldest distributed in garden rockeries. Derived from the type species native to Western Europe and the Mediterranean, it is distinguished by a particularly abundant and homogeneous flowering.

It forms a prostrate and dense carpet, 15 to 20 cm high, with woody branches at the base, covered with narrow, evergreen, dark green leaves, with a slightly rough and ciliated surface, identical to those of the wild type.

The funnel-shaped flowers with five lobes open in a bright sky blue. This particular hue, between azure blue and periwinkle blue depending on the light and stage of bloom, earned it its poetic name. At the peak of flowering, the flowers can literally mask the foliage. In its natural habitat, its flowering extends from March to June; in cultivation, it can start as early as the end of March and continue until July.

In cultivation, it primarily requires well-drained soil and a sunny exposure. It tolerates ordinary substrates, acidic to neutral, or even slightly calcareous, provided the drainage is impeccable and stagnant moisture in winter is avoided. A light pruning after flowering maintains a compact habit.